Drastic increases in the cost of petroleum fuels and electrical energy have forced many energy intensive industries, including the metallurgical industry, to adapt to alternate sources of energy, i.e. regular coal, and to search for means of energy conservation. Many of the metallurgical processes in current use require energy intensive ancillary processes for coke production, pellet production, oxygen production, etc. In most of these conventional processes the sensible heat of the molten metal and waste slag is simply lost. The prior art batch and semi-continuous processes which require transfer of the metal melt from one furnace to another or to and from a ladle all evolve a substantial amount of pollutants and heat into the atmosphere during each transfer and are to that extent thermally inefficient and a source of pollution. Further, the low rate of metal processing in comparison to the high volume of gases which characterizes the conventional processes, requires high surface area of furnace per ton of metal produced and results in correspondingly high heat losses.
Accordingly, it is an object of the present invention to provide a process of high thermal efficiency and low energy consumption for the production of steel and steel products (cast, sheets, strips, powder, etc.) from iron ore, scrap, etc.
It is another object of the invention to provide a thermally efficient process in which regular coal may be used as the only or primary source of energy.
Yet another object is to integrate the various smelting, refining, solidification and shaping steps involved in the manufacture of steel products into a single continuous process wherein the various unit processes are conducted in sealed vessels connected in series.
Yet another object of this invention is total utilization of the chemical energy of coal in metallurgical processes.
Still another object is to provide techniques whereby the sensible heat of flue gases, molten metal, and waste slag can be recovered and recycled within a metallurgical process.
Still another object of the present invention is to provide a process fulfilling the foregoing objectives with minimum atmospheric pollution and heat losses.
Still another object of the invention is the improvement of metal quality by deep refining, controlled solidification, thermal-mechanical treatment and surface protection.
These and other objects and features of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings.